1. Field of the Invention
This invention relates generally to a mixing device. More specifically, the present invention is concerned with a disc-type mixing device useful for mixing, milling or kneading solids such as plastic materials.
2. Related Art
There are known methods in which waste plastic materials are mixed with powdery fillers such as sludge and wood powder for the production of construction materials. The step of mixing or kneading the plastic materials and fillers is generally effected by means of a Bambury's mixer or a biaxial extruder. Such known devices, however, suffer from a drawback that homogeneous dispersion cannot be accomplished even if the mixing step is conducted for a long period of time. In addition, with a mixing device of an extruder type, it is impossible to increase the ratio of the amount of the filler to the amount of the plastic material because of a danger of blockage or clogging by the filler within the cylinder of the extruder.